Scale inhibitor squeeze treatments are widely used to prevent scale in the near-wellbore region of the formation. In conventional squeeze treatments, a volume of brine containing a scale inhibitor is injected into the reservoir. When the well is produced, the scale inhibitor flows
back in the produced water at low concentrations thus preventing scale formation. Typically, scale inhibitor squeeze treatments are conducted in wells that have a significant water cut, providing excellent protection against the formation of scale deposits. However, in wells that have low water cuts or in wells completed to water-sensitive reservoirs,
aqueous scale inhibitor treatments can cause serious problems that may result in lost or deferred production. Oil soluble scale inhibitor squeezes have been used recently in high oil cut wells in the North Sea to avoid many of the problems presented by water-based squeezes.
This paper describes the field implementation and results of a calcium sulfate scale removal treatment and subsequent oil soluble scale inhibitor squeezes into low water cut wells. For these wells, the treatments were designed to provide a technically and economically viable solution to a serious problem.